Mining machine and automatic cycling control mechanism therefor



Filed Dec.

A. L. BARRETT 2,777,102 lMINING MACHINE AND AUTOMATIC CYCLING CoNTRoIJ MECHANISM THERETCR 11 Sheets-Sheet l Hum Hl IEGXGII ATTORNEY Jan. 8, 1957 A. L.. BARRETT 2,777,102

MINING MACHINE AND AUTOMATIC CYCLING CONTROL MECHANISM THEREF'OR Filed D60. 18, 1950 11 Sheets-Sheet 2 iNVENTOR= BrRTl-UR BARRETT ATTORNEY Jan. 8, 1957 A. L.. BARRETT MINING MACHINE AND AUTOMATIC CYCLING CONTROL MECHANISM THEREFOR l1 Sheets-Sheet 3 Filed Dec. 18, 1950 .RNTJH QM QM Nh SN.

INVENTOR: RT-HUR L. BARRETT ATTORNEY Jan. 8, 1957 A. l.. BARRETT 2,777,102

MINING MACHINE AND AUTOMATIC CYCLING CONTROL MECHANISM THEREF'OR Filed Dec. 18. 1950 ll Sheets-Sheet 4 w #MAIN/IVF FIG. 7.

/54 mvENToR:

ARTHUR l.. BARRETT BY q:

ATTORNEY Jan. 8, 1957 A. l.. BARRETT 2,777,102

MINING MACHINE AND AUTOMATIC CYCLING CONTROL MECHANISM THEREFOR l ll Sheets-Sheet 5 Filed Dec. 18, 1950 ENTOR:

ARRET-r QATM INV ARTHUR L.. B

ATTORNEY Jan. 8, 1957 A. BARRETT 2,777,102

MINING MACHINE AND AUTOMATIC CYCLING CONTROL MECHANISM THEREFOR 1l Sheets-Sheet 6 Filed Dec. 18, 1950 .NH @I INVENToR: ARTHUR L. BARRETT ATTORNEY Jan. 8, 1957 A. BARRETT MINING MACHINE AND AUTOMATIC CYCLING CONTROL MECHANISM THEREFOR 11 Sheets-Sheet 7 Filed DeC. 18, 1950 E. im.

mvENToR: ARTHUR' l BARRETT BY M Q 5F ATTORNEY Jan. 8, 1957 A. l.. BARRETT MINING MACHINE AND AUTOMATIC CYCLING CONTROL MECHANISM THEREFOR 11 Sheets-Sheet 8 Filed Dec. 18, 1950 INVENTOR:

rRTHv R L. BARRETT ATTORNEY Jan. 8, 1957 A. l.. BARRETT MINING MACHINE AND AUTOMATIC CYCLING CONTROL MECHANISM THEREF'OR Filed Dec. 18, 195o 1l Sheets-Sheet 9 SMA Jan. 8, 1957 A. L.. BARRETT 2,777,102

MINING MACHINE AND AUTOMATIC CYCLING CONTROL MECHANISM THEREFOR Filed D90. 18. 1950 ll Sheets-Sheet lO I FIG 18 RESERVOIR INVENTORz ATTORNEY Jan. 8, 1957 A. L. BARRETT 2,777,102

MINING MACHINE AND AUTOMATIC vCYCLING CONTROL MECHANISM THEREFOR Filed DSG. 18. 1950 ll Sheets-Sheet 1l FIG. 19.

AXTTORNEY nited States Patent O MINHQG MACHINE AND AUTOMATIC CYCLING CONTROL MECHANISM THEREFOR Arthur L. Barrett, Franklin, Pa., assigner to Joy Manufacturing Company, Pittsburgh, Pa., a corporation of Pennsylvania Application December 18, 1950, Serial No. 201,411

49 Claims. (Cl. 262-29) Continuous mining machines of the type disclosed in i commonly owned patent applications Serial Nos. 102,995 v and 102,996 of lohn D. Russell and .lohn R. Sibley, respectively, and both tiled July 5, 1949, provide a considerable `advantage over older and more conventional methods of mining in that they eliminate the dangers which go along with blasting, and substantially increase the tonnage per man-shift. A further improvement could be effected by providing means to operate such a machine, or at least aV substantial portion of its operating cycle, automatically.

lt is, accordingly, an object of this invention to provide a continuous mining machine which is substantially automatic in its operation. The particular and specific embodiment of the continuous mining machine shown is one in which a vein-attacking and disintegrating instrument is mounted for a plurality of movements in a coal face. The above and other objects are achieved in the embodiment of the machine shown by limit means postitioned to be actuated as each separate operation of the cycle nears completion, thus initiating the next succeeding operation. The limit means referred to may be hydraulic or electric, and may operate with hydraulic or electric mechanism.

In the drawings:

Fig. l is a top plan View of the forward end of a mining machine of the type referred to above, showing the vein-attacking and disintegrating instrument and immediately associated mechanism.

Fig. 2 is a side elevation View of substantially that portion of the machine shown in Fig. l.

Fig. 3 is a view in section on a substantiallyhorizontal plane, showing some details of the machine, and being on a larger scale than Figs. l and 2.

Fig. 4 is a schematic view of a hydraulic automatic mechanism for a mining machine of the type shown in Figs. l-3.

Fig. 5 is a detail view, being a View partially in section of the slave cylinder and the operating cylinder for the selector valve and being on a larger scale than Fig. 4.

Fig. 6 is another detail view, again being a partial sectional view showing the one-way drive mechanism for the selector valve, and being on a larger scale than Fig. 4.

Fig. 7 is a detail View, on an enlarged scale, showing ice Patented Jan. 8, 1957 Fig. l1 is another view similar to Fig. 8 but showing the valve in position for the lowering or downswing operation.

Fig. 12 is a view in section substantially on line 12-12 of Fig. 9. v g

Fig. 13 is a view in section substantially on line 13-13 of Fig. 11. y

Fig. 14 is a view in section on line 14-14 of Fig. 12.

Fig. 15 is a schematic View of another embodiment of mechanism `for making the mining machine automatic.

Fig. 16 is a third embodiment of the invention showing a schematic view of still another automatic mechanism. i

Fig. 17 is a schematic View of atourth embodiment of the invention. i

Fig. 18 is a schematic view of a fifth embodiment of 'y the invention.

Fig. 19 is an operational view, showing a horizontal section through a portion of a mine, in which the mining machine is seen in plan.

Fig. 20 is a section on a Vertical plane showing the mining machine of Fig. 19in side elevation.

The forward end of a mining machine of the type described is shown in Figs. 1 and 2'. ,The machine comprises a mobile base mounted on a caterpillar track 2, a vein-attacking and disiutegrating instrument 4, which is mounted for swinging in vertical planes about a "horizontal axis shown lat 6 of Fig. 2, the axis being the axis of the shaft carrying the drive sprockets for the chains of the vein-attacking and disintegrating instrument 4. vThis shaft is not shown in detail here, but can be seen readily by reference to the above-identified, application Serial No. 102,996.1 The vein-attacking and disintegrating instrument is mounted for sliding or rectilinear movement on a sliding frame or support 8 which reciprocates on andV relative to la horizontal supporting frame or turntable 10. The turntable frame 10 is swingable in a horizontal plane about a vertical axis,v which vertical axis is v,the sumping-in and4 retracting ,movement. The rectithe mechanism for holding the selector valve in an opery ating position.

Fig. 8 is an enlarged Vview in section through the selector valve to show internal construction, and showing the selector valve in position for the sumping-in operation.

Fig. 9 is a view similar to Fig. 8, but showing the valve in position for the upswing operation.

Fig. 10 is a view similar to Fig. 8, but showing the valve in position for the retract operation.

linear movement is provided by the sump cylindersA 16. Swinging of the instrument 4 in vertical planesis accomplished by means of the upswing cylinders .18.

' Swinging of the turntable` frame 10, and with it the instrument 4, in a horizontal plane is accomplished by means of the swinging cylinders 20. As will readily be understood by reference to the above-identified Sibley application, the cylinders 20 carry pistons having pistonrods which are anchored to a stationary portion of the machine frame. To the exterior of the cylinders Z0 there is secured a pair of sheaves 22 around which are wrapped chains 24. Chains 24 arev secured at one end to the stationary frame by means of la resilient shock absorbing mechanism indicated generally at 26. The chains wrap around other sheaves 2S and 30, and at their other ends i are secured at 32 to the swingableframe 10.

ln the schematic views (Figs. 4 and 15-18), the two sump cylinders are represented by a single sump cylinder 16, the two upswing cylinders are represented by a single cylinder 18, and the two horizontal swing cylinders are represented by a single cylinder 20.

The hydraulic automatesystem Reference will now be hadrto lFigs. 4*-14 for a detailed consideration vof the hydraulic automatic mechat 3 nism. A tank or reservoir 34 `is provided with a supply of hydraulic uid. A hydraulic pump 36 of any satisfactory design, driven by ahy desirablepower source (not shown) is connected with thereservo'ir by a conduit 38 and discharges nt a discharge line 40. The line or conduit 40 connects the pump 36 with selector means, such as valve 42.A t 4 There is provided in the pump discharge liner 40 a manually operable valve 44. A by-pass line or conduit 46 connectsone port of valve 44 with the pump discharge conduit 40 and is adapted to connect through the valve 44 to reservoir 34 by way of a byepass conduit 48. The valve 44 will preferably be a conventional three-position, manually operable valve, having one position in which all ilu'id owi's cut oi, another position in which iluid flow through the pump discharge line 40 is permitted, and another position in whichhydraulic fluid under pressure is by-passed backto the reservoir by Wayof conduits 46 and '48.` Valves of the type indicated at 44 are stock items which are readily available, so it is not necessary to describe valve 44 indetail.

The selector valve 42` is, in eifect, a distributor valve and is providedwith a conduit 50 connecting the valve 42 with the tank or reservoir 34, a conduit 52 connecting valve 42 with one end of the sump cylinder 16, a conduit 54 connectngthe valve 42 with the other end of the sump cylinder 16, and a conduit 56 connecting 4 the valve 42 with the upswing cylinder 18.

It will, of course, be understood by those skilled in the art that the single cylinders 16, 18,."and 20, shownin the schematic views, are 4merely representative of the hydraulic motive power shown in Figs. 1-3.

The selector valve 42 and its associated operating mechanism` are `more generally described `asselcctor means; having a given orientation for each operation `of the vein-attacking and disintegrating instrument 4. More specifically, the valve 42, shown in Fig. 4, is a master selector which has a given operating position for each operation of the: instrument 4, and which is movable into those operating positions in a certain sequence by means which are shown` in detail in Figs. 4-14 andwhich will nowbe described. t

Sump cylinder 16 is, in effect, a hydraulic motor having a piston rodor drive member() (see also Fig. 3) connected to the' sliding frame 8 to etect the rectilinear movement `referred to above. Similarly, upswing cylinder 18 is a hydraulic motor having a piston rod or drive member 62 connected to etect the swinging movement in vertical planes` referred` to above. Limit means 64,

66, .68, 70 and 72 are provided to be engaged by some portion of the moving parts of the machine n ear the ends of the various operations of` the operating cycle; It

will, of course, be understood by those skilled in Vthe al that the limit means may be disposed in any convenient location foractuation by any suitable portion or portions ofthe machine.y However, forthe sake of convenience, the limit .means are herein shown schematically as being engaged by armsror projections attached tothe piston rods 60 and 62. More specically, an arm or projection 740m `the rod 60 is in position to actuate limitrmeans 64 and 70; an arm or projection 76 on piston rod 62 is` in position to actuate limit means 66 and 68; and an arm or projection 78 is also carried by piston rod 60 in such a manner as to actuatethe limit means 72. The limit means are simply cylinders with pistons reciprocable therein, the piston rods extending out through the cylinders at one enclin position to `be actuated by one of theprojections 7,4,` 76 or 78. The end of each cylinder .opposite the piston rod end is connected with conduit 80and conduit 80 `connects with a oylind'er82 (Figs. 4 and Cylinder 82 is provided with a bore 84 in which reciprocates a iloating piston 86. Piston 86 is provided with a skirt 8S whichwserves `as a control valve for the means which changes the orientation of `the 'master `selector 42. More specifically, the skirt 88 is provided with with conduits 92 and 94 and in another position registers with conduits 96 and 98. Conduits 92 and 96 both connect with a conduit 100 which connects with a luid motor 102.

Piston 86 is preferably hollow to receive a spring 104. The spring 164 is in compression, one end resting against the piston and theH other `end resting against the opposite end wall of cylinder 82. Spring 104 biases the piston 86 into an operating position in which conduit 92 communicates with conduit 94 by way of groove 90. When piston 86 is pushed to the `extreme right limit of its travel by the provision of uid pressure `through conduit S0, groove is in position to communicate conduits as and 9s. y

A hydraulic accumulator 106 of the type disclosed in MercierPatent No. 2,256,835, reissued December 4, 1951, No. Re; 23,437,`is connected with the pump discharge line 40 by a check valve 108 and a conduit 110. The aforesaid conduit 98 is connected with conduit 110 in order to receive iluid from the accumulator 106. ltmay be pointed out here that in many applications it may be desirable to dispense with the accumulator, in which case the conduit 98 will be connected directly with the pump discharge conduit 49. Conduit 94 is a hydraulic fluid exhaust line which connects with the tank 34 by way of exhaust line or conduit 50.

A manually operable valve 112 is provided, being connected with the conduit by a conduit 114 and a branch conduit 116, and connecting with conduit 94 by a conduit 118 and with conduit 98 by a conduit 120. The valve 112 is preferably a three-way valve having one operating position in which no uid flow `is `permitted through the valve; a second operating position in which fluid flows from conduit 120 to conduit 114 by way of branch conduit 116; and a third operating `position in which fluid flow is permitted from conduit 114 to the tank 34 by way of conduits 118, 94, and '50.

Each of the limit means 64, 66, 68, and 7) constitutes, in effect, a mastercylinder which controls the operation of the slave cylinder 82. A reservoir 122 is connected with the conduit 80 through a check valve 124 and a relief valve 126. The check valve 124 insures that thc hydraulic system comprising the conduit 80 `and its connected cylinders shall always be full of hydraulic fluid, and relief valve. 126 insures against excessive pressures building up in the system for one reason or another, as for example, inthe event that one of the limit means should stick instead of returning to its neutral position.

Reference is now had to the iiuid motor 102 and to its drive connection with the valve 42, best shown in Figs. 5-7. Fluid motor 102 is preferably `a hydraulic cylinder in which a piston 128 is reciprocable. Piston 128 is biased leftward as seen in Fig. v5 by a spring 130. A stepped piston rod 132 provides a driving connection between piston 128 and a yrack 134. A pinion 136 meshes with the rack `134.

Pinion 136 has a one-way drive connection withthe rotatable valve body shaft 138 `of valve 42. lf desired, this one-way drive may be provided by means of a ratchet and pawl mechanism, but a preferred form of drive is that shown in Fig. 6. Gear or pinion 136 is provided with a plurality of pockets or recesses 140. In each recess 140 a ball 142. is located. Balls 142 engage slightly curved surfaces 1'44 on the shaft '138.` The surfaces 144 may, if desired, be plane, but are shown in Fig. 6 as curved surfaces having 'a relatively long radius. Recesses `140v are provided with surfaces 146 which are struck from the same centers as the surfaces 144. The surfaces 146 are bounded at one end by spherical surfaces having substantially the curvature of the balls 142, and at their opposite ends intersect withother surfaces 148 which are curved and are struck from the center of the pinion 136 (which is also, of course, the center of the shaft 138). The surfaces 148 are also bounded by spherical surfaces having the same curvatureas the balls pinion 136 and provide for clearance of the corners of the nearly square portion of shaft 138.

In order to insure a precise positioning or orientation of valve 42 for each operation of the cycle, a detent mechanism, such as is shown in Fig. 7, may be provided. Fig. 7 shows a squared portion 152 of shaft 138 provided with four recesses 154. The recesses 154 are spherical and have the same curvature as a .ball 156 which is heid in a recess 158 provided in the housing of valve 42. Ball 156 is spring-biased into an alined recess 154 by means `of a spring 160.

Reference will now be had to Figs. 8-14 for a detailed discussion of the selector valve 42. Valve 42 comprises a valve housing 16,2 having a cylindrical bore 164; an end cover plate 166; an end cover plate 168; and a valve body 170 rotatably disposed in the cylindrical bore 164. T he housing 162 is provided with a number of passages: a substantially radial passage 172 and a passage 174 intersecting the passage 172 and connecting at its other end with the conduit 52; a substantially radial passage 176; another passage 178 intersecting with passage 176, still another passage 180 intersecting passage 178 and in communication with conduit 56; a substantially radial passage 182, and another passage 184 intersecting passage 182 and connecting with conduit 54; a substantially radial groove 186 (Fig. 14) intersecting at one end. with an arcuate groove 188 and at its other end with a groove 190 which is in communication with conduit 50 to the tank; and a plurality of longitudinal passages 192, 194 and 196 connecting the arcuate groove 188 with the bore 164. The end cover plate 168 is provided with cooperating grooves 188' and 190 which, together with the grooves 188 and 190 respectively, in the housing 162, form complete iluid passages. The end cover plate 166 is provided with an axial passage 198 which is in communication with the pump discharge conduit 40.

The rotatable valve body 170 is also provided with passages: an axial passage 200 which is at its one end always in communication with the aforesaid passage 198, and, intersecting with the other end of passage 200, a radial passage 202 which communicates in turn with the passages 172,'v 176 and 182; a longitudinal passage 204 which communicates in turn with the longitudinal passages 192, 194 and 196, and a tangential passage 206 which intersects at its one end with the longitudinal passage 284, and at its other end communicates in turn with the passages 172, 176 and 182.

The automatic hydraulic swing means Reference is now made again to Fig. 4 for a description of the automatic control mechanism for the swing cylinders 20. The aforesaid master cylinder 72 is connected by a conduit 210 with a slave cylinder 212. The slave cylinder 212 will be substantially the same as the slave cylinder 82, so a detailed discussion thereof is not warranted. The hydraulic system of master cylinder 72 and slave cylinder 212 is kept full by a gravity reservoir 214, as will be understood by those skilled in the art, the reservoir 214 being connected with conduit 210 by conduits 216 and 218. The conduit 216 is provided with a relief valve 220 and the conduit 218 is provided with a check valve 222.

Slave cylinder 212 operates a control valve to regulate the supply of fluid under pressure to the swing cylinders in substantially the same manner as slave cylinder 82 operates the control (groove 90, Fig. 5) for the fluid motor 102. To this end, `conduit 98 has connected therewith one end of a conduit 224, the other end of which connectswith the bore of the cylinder 212. Diametrically opposite the conduit 224 is another conduit 226 which connects with a conduit 228. Conduit 228 connects by way of a conduit 230 with thev bore of cylinder A212 -in another location, and diametrically opposite the conduit 230 is another conduit 232 which is connected with the hydraulic iluid discharge line 94.

Conduit 228 connects with a four-way valve 234. A conduit 236 connects valve 234 with the spent hydraulic fluid conduit 94, and conduits 238 and 248 connect with the bore 242 of a cylinder 244. Diametrically opposite the conduits 238 and 240, conduits 246 and 248 respectively also connect with the bore 242. A conduit 250 is tapped into conduit 228 between conduit 226 and valve 234, and connects conduit 228 with the right end (as seen in Fig. 4) of cylinder 244 by way of a conduit 252. A conduit 254, having therein a check valve 256, connects the conduit 252 with the pump discharge line 40. Opposite the conduits 238 and 240, conduits 246 and 248 connect with the opposite ends of the swing cylinders, shown schematically in Fig. 4 as a single swing cylinder 20.

A manually operable valve 258 is connected with conduits 246 and 248 by means of conduits 260 and 262 respectively, and connects with the pump discharge line 40 and tank 34 by means of conduits 264 and 266 respectively. Manually operable valve 258 is a threeposition valve which for automatic operation is positioned to prevent fluid llow through its connected conduits, and which has one operating position connecting conduit 260 with conduit 264 and conduit 262 with conduit 266, and another operating position for connecting conduit 268 with conduit 266 and conduit 262 with conduit 264.

A piston 268 is reciprocable in bore 242 of cylinder 244, being biased toward the right by a spring 270. Piston 268 is provided with spaced peripheral grooves 272 and 274, which in one operating position of piston 268 are adapted to connect conduit 238 with conduit 246 and conduit 240 with conduit 248.

A piston rod 276 extends out through one end of cylinder 244 and carries a cam follower 278. Cam follower 27 8 has a camming surface 280 which is adapted to engage substantially identical cams 282, 284 and 286. The cams are movable with respect to the cam follower by mounting either the cams or the cam follower on a portion of the machine which swings in a horizontal plane and mounting the other element on a portion of the mobile base.

The cam follower 278 is mounted for pivotal movement, enabling it to take positions off center with respect to the piston rod 276 and thus with respect to the cylinder 244. Thus, as will be undersood by those skilled in the art, cam follower 278 is pivotally mounted by means of a pin 288 on a head 290. Head 290 has an arcuate surface 292 which cooperates with a mating arcuate surface 294 on the cam follower. ln one direction (clockwise, as seen in Fig. 4) the arcuate surface 292 is interrupted by a stop 296 which is adapted to engage an extension 298 on the cam follower 278. Springs, not shown, will be provided and will be connected to hold the cam follower 278 in its centered position shown in Fig. 4.

The cam follower 278 is yieldably, and at the same time rotatably, carried on piston rod 276 by a hollow cylinder 300 threaded at one end and closed by a cooperating threaded member 302. The threaded member 302 has a substantially central opening through which passes piston rod 276. The end of piston rod 276 has a steppeddown diameter to receive a nut 304. Nut 504 holds a collar or washer 306 against the shoulder provided by the larger diameter of piston rod 276. Collar or washer 306 engages one end of a spring 303, the other end of the spring abutting against the bottom of the recess or hollow in cylinder 300. Thus, the cylinder 300 provides a yieldable support for cam follower 278 on piston rod 276 and also a-llows cam follower 278 to turn on the axis of piston rod 276 in order to allow automatic operation for swinging in either direction.

The electrical system of Fig. 15

Reference is now made to Fig. 15 in which the selector valve is the same to t'he entent that 'the master 'selector 42 is `substantially identical, the diie'r'ne lyin'g'in 'the means toforent the master selector valv'; a further difference in the automatic control means of Fig. l5 over that shown in Fig. 4 lies in the automatic means 'for swingin'gthe vein-attacking and disintegrating instrument in a horizontal plane. n p

The orientation-changing means in Fig. 15 includes substantially the 'same rack-and-pinio'n device consisting of a rack `134' and `a pinion 4136'. However, in the embodi ment shown in Fig.V l5, an electromagnetic device, indi cated generally at 310, is connected to reciprocate the rack 134'. More specifically, a coil 3`12 is connected in apower circuit and when energized moves an 'armature 314 Vwhich fS'Corllicttl lto the rack 134. A Spring 316 is connected to returnthe armature 314 to its de-energized position shown in Fig.,15.

One end of lcoil 312 is connected to the positive side 317 of a iD. C. power source by a conductor 318, and

the other end of coil 312 is connected by a conductor 320 with a stationary contact 322 of a set of normally open contacts. The other stationary contact 324 thereof is connected by a conductor 326 and a conductor 328 with thel negative side 329 of the D. C. power source. A

bridging contact 330 of the set of normally open contacts is adapted to be movedinto circuit closing position by a solenoid comprising a coil 332 and an armature 334.

The coil332 is an element of the control circuit for the automatic system which is responsive to completion of one operation of the machine in order to initiate the next operation. The control circuit includes a plurality of limit switches positionedin any suitable manner and loca tion on the machine such that they will be actuated upon completion of a given operation. In the embodiment shown, the limit switches are illustrated as being in posi- 332 is connected to a conductor 376 which in turn connects with two branch conductors 378 and 38S. Branch conductor- 373 is Y in electrical contact with stationary contacts382 and 3840i limit switches 364 and 366 respectively. Branch conductor 380 is connected with stationary contacts 386 Aand 38S of limit switches 368 and y 370 respectively, the 'connection with contact 388 being by way of another branch conductor 390.

`Referring again to limit switch `364, a stationary contact 392 is disposed opposite stationary contact 382, and a bridging Contact 394 is adapted to connect the contacts 382 and 392 electrically when switch 3 64 is actuated. Stationary contact 392 is connected'electrically by a con ductor 396 with `a stationary contact 398 of limit switch 366. Another stationary contact 40B opposite contact 3 9`is adaptedto ibe electricallyconnccted with contact 398 by a bridging Contact 402 when switch 366 is actuated. Alconductor 404 electrically connects stationary contact 460 of switch 366'with a stationary Contact 406 of switch 368.` Opposite contact 406 there is another stationary contact '408, and the two contacts 466 and '408 are adapted to be connected electrically by a 'bridging contact 410 upon actuation of the limit switch 368. Stationary contact 403 is electrically connected by a conductor 412 with a stationary contact 43.4 of switch 370,`the Contact '414 being 'opposite contact 388, referred to above, -of limit switch 370; a bridging'contact '416 is positionable to close an electric circuit between stationary contacts '388'and 414.

` Referring again to switch 366, a stationary contact 418 is disposed opposite Contact 384, 'and a bridging contact 42,0 is pqs'ition'able "to close 'an 'electric circuit betv'fee'nth'em. Stationary' 'Contact 418 is electrically connected by`w`ay 'of a conductor `422l`with a 'stationary contact 424 of liniit switch In limit switch 370, there 'is a stationary contact 426 opposite the stationary Contact 424, and a bridging Contact 423 is positionabic upon actuation of the switch to complete an `electric circuitbetw'een contacts '424 and 426. Stationary contact 426 is connected with one side of a D. C. power source; as shown here, contact 426 is` connected with the negative side 329 of the D. C. power source by a conductor 430. As is readily seen by reference to the drawing, the negative side 329 of the line is electrically connected with conductor 404 at 434.

ln limit switch 364, there is another stationary Contact 436 which is connecteduwith the negative side 329 of the line by a conductor 43S. Another stationary contact 44d is in position to be connected electrically 4with stationary contact 436 by a bridging Contact 442. Contact 440 is electrically connected by way of a conductor 444 with a stationary contact 446 of limit switch 368. A bridging contact 448 is positionable to close an electric circuit between stationary contacts 386 and 446.

The automatic electrical swing `mea/is The automatic mechanism for eifecting horizontal swinging of the vein-attacking and disintegrating instrument about a vertical axis is accomplished somewhat differently in the embodiment shown in Fig. 15 from the embodiment shown in Fig. 4. In the embodiment shown in Fig. 15, a branch conduit 264 connects the pump discharge conduit 40 with a two-way valve 450. A return line conduit 266 connectsthe valve 450 with `the tank or reservoir 34.

. Valve 450 is a simple two-wayyalvc having only two operating positions; namely, open and closed. Valve 450 has two conduits, 452 and 454, connecting with a four-way valve 456. When valve 450 is in its open operating position, conduit 264 is in communication with conduit 454, and conduit 266 is in communication with conduit 452. When valve 450 is in its closed operating position, 'then of course there is no fluid flow through the valve.

Four-way valve 456 has two additional conduits, 458 and 460, connecting valve 456 with the swing cylinder 20. lt will be appreciated by those skilled in the art that valve 456 has two operating positions, in one of which conduit 452 and 458 are connected, and conduits 454 and 460 are connected; and another in which conduits 452 and 460 are connected, and conduits 454 and 458 are connected.

Means are preferably provided to accomplish lzori zontal swinging manually by by-passing the automatic control valve 450. To this end, a manually operable vvalve 462 is connected by way of a conduit 464 with the source of fluid supply and by way of the conduit 466 with the tank 34. Conduits 468 and 470 connect the valve 462 with opposite ends of the swing cylinder. As will readily be understood by those skilled in the art, the valve 4'62`is`one whichmay be any one of a number of valves suitable'for the purpose, having three operating positions: one in which conduits 464 'and 468 are connected, and conduits 466 `and 470 are connected; another in which conduits 464 and 470 are connected, and conduits 466 and 468 are connected; and a third position in which no uid flow through the valve is permitted.

Valve 450 may be any one of a number of suitable solenoid-operated valves. Power for the operation of valve 450 is supplied through a power circuit whichinclude's 'a portion of conductor 318 connected with the positive s'ide 317 of a D. C. power source, a conductor 472, the 'operating coil of 'valve 450, a vconductor 474, af'sftatioh'arf'y contact '476,V`a second stationary contact '478, a 'bidging'cotct'480 po'sitio'n'able to "complete a circuit between contacts 476 and 478, and a conductor 482 connecting stationary contact 478 with the negative side 329 of the D. C. power source by way of conductor 328.

A control circuit is provided to control the completion and interruption of the power circuit just described. This control circuit includesv a coil 484 of a solenoid having an armature 486. .One end of coil 484 is connected with the negative side of the D. C. power line by a conductor 488 and the above described conductors 482 and 328. The other end of coil 484 is connected by a conductor 490 with a stationary contact 492. Another stationary contact 494 .is disposed opposite contact 492, and a bridging contact 496 is positionable to close an electric circuit between contacts 492 and 494. A conductor 498 connects stationary contact 494 with a stationary contact 500 of limit switch 372. A second stationary contact 502 of limit switch 372 is connected with fthe positive side 317 of the D. C. power line by a conductor 504. A bridging contact 506 is positionable upon actuation of switch 372 to complete an electric circuit between contacts 500 and 502.

The moving or bridging contact 496 referred to above is mounted to be moved upon horizontal swinging of the vein-attacking and disintegrating instrument about the vertical axis referred to above. To this end, a plurality of stationary cams, some of which are shown at 507, 508, and 510, is in position to be' engaged by a cam-follower 512. Cam-follower 512 is connected to effect movement ofl bridging contact 496 by means of u a connecting rod 514.

It can be seen that the cam-follower 512 has a retracted position in which contacts 492,494, 496 are open, and an extended position in' which the contacts 492, 494, 496 are closed. I

A circuit is provided in parallel with the circuit comprising contacts 492, 494, 496. This circuit includes a conductor 516 connected with conductor 498, a conductor 518, stationary contacts 520 and 522, a bridging contact 524, and a conductor 526. n

Bridging contact'524 is normally closed, and is mounted to be moved into open circuit position by energi'zation of a coil 528 of a solenoid; for this purpose an armature 530 is connected to move bridging contact 524, and is positioned to be moved by coil 528. One end of coil 528 is connected to conductor 516, and the other end of coil 528 is connected with conductor 482 by a conductor 532.

As will be understood by those skilled in the art, the solenoid vfor coil 528 and contacts 520, 522, 524, is preferably a normally-closed, time-delay-opening solenoid, such as is readily available from a number of commercial sources.

The electrical system of Fig. 16

Reference will now be had to Fig. 16, lshowing another embodiment of the invention. In this embodiment the limit switches are substantially identical with the limit switches of the embodiment shown in Fig. 15. Accordingly, the limit switches will not be discussed in detail here, but will only be referred to generally by the reference characters 364, 366, 368, 370, and 372, those being the reference characters used in referring to the same limit switches in Fig. l5. f

ln Fig. 16 the system provides motor means connected to be operated by actuation of the limit switches. As in the embodiment shown in Fig. l5, the selector means is electrically operated and additional motor means are connected to orient the selector means for the several operations of the vein-attacking and disintegrating instrument.

More specically, the additional motor means is a rotary electric motor having an armature, or rotor, 534 connected to the selector valve 542 by means of a shaft indicated diagrammatically at 544. The motor shown is a D. C. motor, and the power source shown in the tual D. C. power source available in mining operations, but it will of course be understood by those skilled in the art that alternating current may be used.

In the embodiment shown, the motor armature circuit is connected with the positive side 546 of the power source by a conductor 548, and the opposite brush of the motor is connected by a conductor 550 with a stationary contact 552. There is thus a power circuit comprising the positive side 546 of the line, conductor 548, motor 534, conductor 558, the aforesaid stationary contact 552, a second stationary'contact 554, a bridging contact 556 positionable to close a circuit between contacts S52 and S54, and a conductor S58 to the negative side 560 of the D. C. power line.

The system provides means to stop motor 534 after rotation through a predetermined are in order to permit precise positioning of the selector valve 542. This means to stop motor 534 after a predetermined rotation includes the normally-open contacts 552, 554, 556, and electromagnetic means to close the contacts comprising a solenoid having a coil 562 and an armature 564. One end of coil 562 is connected to the conductor 558, and the other end is connected to the positive side of the line through a conductor 566, a stationary contact l568, a bridging contact 570, a stationary Contact 572, a conductor 574, conductor 576, through any two of the limit switches 364, 366, 368, 378, and conductor 578.

The contacts 568, 570, and 572, are normallyclosed time-delay-opening contacts ofa solenoid having a coil 586, and an armature S82. One end of coil 580 is con-- nected to the conductor 558, and the other end is con-- nected to the conductorl 574.

A second limit switch v584 is connected in parallel with the normally closed, time delay-opening, contacts: 568, 570, 572. The limit switch 584 comprises a stationary Contact 586 and a movable contact 588; the contact. 586 is connected with conductor 566 by a conductor 590. Contact 588 is electrically connected with conductor 574 by means of a cam follower 592 on which contact 588 is mounted. The cam follower 592 is shown as beingv hinged for pivotal movement at its point of connection to conductor 574. The other end of the cam follower 592 is engaged by a cam 594 having a lobe 596. Cam 594 is mounted for rotation by the armature 534, being connected therewith by any suitable means, as for example a shaft shown diagrammatically atr 598.

In the preferred embodiment of the form of the invention shown in Fig. 16, still another, third, limit switch indicated generally at 688 is provided in parallel with the limit switches 364, 3:66,v 368, 370. The third-named limit switch 600 comprises a stationary contact 682 and a movable contactf604. Stationary contact 602 is connected with conductor 576 by a conductor 686. Movable contact 604 is electrically connected with conductor 578 by a cam follower 608, on which the contact 664 is mounted.

Cam follower 668 is shown as being hinged at its point of connection to conductor 578, and at its other end rests on a cam 610 having a lobe 612. The cam 618 is likewise rotated by the motor having the armature 534, referred to above, being preferably connected with shaft 598 for such rotation.

It will be understood by those skilled in the art that the limit switches 584 and 660 are normally open switches, the lobes of the cams being normally in engagement with their respective cam followers. The cams 594 and 6m are normally rotated through one revolution for each operation in the complete operating cycle of the The lectriczl 'automatic nechtnsm sh'own in Fig. 17

`A fourth embodiment of the invention, shown in `Fi'g. 17, likewise is an electrical system, but ditiersfsomewhat from the system shown in Figs. l5 and 1'6. `A major'difference lies in the different form which the selector means takes, and another major difference lies in the limit switches actuable by movement of the vein-attackingfand disintegrating instrument `and their associated :electric circuits.

In the embodiment shown in Fig. 17, a reservoir or tank 34 similar to the reservoirs shown in the other systems is provided and supplies hydraulic lluid to a pump 36 through `a fluid conduit 3S. 4Thepump discharge con duit 40 is shown in Fig. l7 as connecting with 'branch conduits 61'4 andf616, Branch conduit61'6 has connected with it still another branch conduit618. Selector means for the embodiment shown inFig. l7 comprises two valves 620 and 622 shown-as being @connected -with `.iluidconduits 614 and 618 respectively.

The valves 620iand622are shown in Fig. l7as being connected in parallel `with ipump 36. This showing is for the purpose of `simplifying the rschematic diagram illustrating the invention. Thevalves may in actual practice be thus connected, but Vthey may .also beconnected in series. 'as will be understood -bythose skilled in the art.

Valve 62) has 4a discharge conduit 624Yconnecting with tank 34, and valve 622 -has 'a discharge conduit 626 con necting with tank 34. AValve 620 has conduits l628 iand 630` connecting wththe right and left ends, respectively, of sumpcylinders 16. Valvei 622 has a single conduit 632 connecting withthe upswing cylinders "18.

As will be understood by those 'skilled in the` art, the valves 626 and 622 may be 1anysuitable-'4-way, closed center spool, spring centered, double solenoid operated hydraulicvalves. Valveslof thetype referred to are available commercially and need not be detailed here.

The valves "620 'and 1622 are preferably Substantially identical, the second `pressure lineofvalve622, omitted here to simplify-thedrawing, being `jumpereil'back t'o tank 34 by means which ywill `be understood bythose skilled in the art.

Valve 620 is` provided with operating solenoids 634 and 636. When solenoid 634 is energized, conduit 614 is connected with conduit 628, andcondnit630 isconnectetl with conduit 624. When solenoid 636 islenergized, conduit 614 is connectedlwith Iconduit 630and' conduit-628 is connected with conduit `624. When bothsolenoids are deencrgized, the valve .is spring-centered fand Lthere is no flow permitted through the'valve.

Similarly, valve 622 is providedwith solenoids "638 and 640. When solenoid1638 is energized, 4conduit `618 is connected with conduit 632, and the jumperedoutlet from valve 622 is, of course, connected with` conduiti626. When solenoid 640 is energized, conduit 632 is connected with conduit 626 and conduit 618 is connected with Ltank 34 by the jumpered connection referreditoabove. With both solenoids 638zand 640 deenergized, the valve is centered by its spring and there is no llow permitted.

The positive side 642 of a D. C. power source is shown as being provided with branch conductors 644, 646, 648, 650, 652 and 654. Branch conductor 648 goes to a stationary Contact 656; anotherstationary contact 658 -is opposite the contact '656, *and a bridging contact'660 is positionable to complete a circuit between the contacts 656 and 658.

Sumpv and swing cylinders .116 and'18 areprovidedwith the usual piston rods'60 and 62, respectively, and Ithese piston rods themselves carry limit switch actuating pro jections 74 and 76, respectively. The contacts`656, 65.8,

660 lform a limit switch indicated generally at 664 which corresponds tothe limit switch 64 shown. in Fig. 4fand theli'r'riit switch 364 of Figs. Kl5 "and I'6. "Similarly, ther limit switches 666, "668,""670"'an`d 672 Aare provided 'as 1,2 shown, asptartsofthe means to initiate the various operationsotlthe'maclne.

Limit switch 666 is provided with stationary contacts 674 and 676 and a bridging `contact 618i). Limit switch 668 .isprovided with stationary contacts 682 and `684, and a bridging Contact 686. Limit switch`670fis provided with stationary contacts 68S and S696, iand a bridging contact 692. nd "limit switch 672 ,is provided with stationary contacts '694 and 696,anda bridging contact 698.

'Thelimit switches 664,-5666, 668 4and 670 are connected to operate the selector meanstcornprising `valves 620 and 622. They operate 'the valves 620 `and 622 by operating the electromagnetic actuating means consisting of the solenoids 634, '636, `638 and 640. The connection .for such operation includes a ,plurality Aof `electric Vmotor means 760, 702, '70'4 and T706. 'Each of the `aforesaid electric motor carries a set of normally open `contacts and a 4set of normally closed contacts. Each of the `electric motor means` also comprises an armature connected toclose the normally open contacts and open the vnormally :closed contacts, and a coil connected/to .be energizedby the-closing of an appropriatelimit switch `to ymove the coils associated armature.

YMore specically, motor r means 700 is provided `.with anarmature 708 connected to close normally open contacts 710, '712, 714 andto .open normally vclosed `contacts 716,173,720.` Armaturel708 is adapted to be moved Vby ccd1-722, ion'eend of which fis .connected with contact 658 of lrriitsw'itch` 664 `by .a conductor 724, `and the other end o'fwhich is connected to the negative side y'726 of the D. C. powerV source by branchconductors 728 and 730.

vElectric-rnotor-means 702-is provided lwith an armature 73'2tcarr-ying .normally .open contacts 734, 736,` 738 and normally closed contacts 740, 742, 744. Armature 732is adapted to.be moved by 4a coil 746 which has-one end connected;tocontact-674 :of limit switch 666 by means of a.conluctorT/'48, thetotherendtof the coil beingrconnectedwiththenegative side 726 tot the power sourceby wayo'f conductors 750 and 752.

Electric motorrneans 704has:an armature 75'4 iwhich carriesmormally opencontacts 756, 758, 760 and -normally closed .contacts A7.62, .764, 766. Armature 754-is adapted to be. .moved =bythe euergizationof a -coil 768, tone end of whichmonnects "with :contact.-690 of limit switch'670 by a conductor i770, .the otherend of `the'coil being con nected l-wtlnthe negative sidei7261of lthe line by Ia branch conductor 772.

.Electric tmotonmeans 706 basan armature `77.3 which carriesanormallyiopen contacts `IV/'4, 775, 776 and :normallyclosedzcontacts 277-7, 778, 779, Armature 773 `is adapted .toloe moved by -a Vcoil 780, one end of which is connected to contact 634 of switch 668 by a conductor 781, and the other end of which is connected to thc negative side726of'the`D. C. 'power source.

The .coil1of Vthei.electromagnetic actuating `means 634 of valve 626-.isxconnected with `branch conductorrr654 by, another =branch`conductor `'788Vand is connected with thenegative iside l726 .of `.the power source through conductor`790, normallyclosedfcontacts 7,16, 71S, 472() of eleetiomotormeans700, conductor 792, contacts 774, 775,'776of`the morma'llyfopen set of contacts of electric motor .means 7tl6,.and branchtconductor 794.

The coil of the electromagnetic actuating moans :636 is connected-with conductor-654'by another branch conductor 796,:and with the negativeside offthe line by `a conductor :798,tnormally open contacts 734, 736, Y732i fot motorrmeans '202,tconductori800, fnormally closed contarots176227647766offmotor means`704, and branch conducto'rSU-Z.

The coil of the electromagnetic actuating means 638 is connected 'with branch `'conductor '654 by another branch conductor"8`0'4,"an`d 'with thenegative side o'f the power 'source through azconductoril`6, normally .closed contactsh740f742j744 of electric motor means '702,

'armies 13 conductors808,l normally open contacts 710, 712, 7-14 of electric motor means 700, and -branch conductor 728. 1`he coil of the electromagnetic actuating means 640 is connected with branch conductor 664 by another branch conductor '810, and with the negative side of the power source by means of a conductor S12, normally open contacts 756, 758, 5760, conductor 8114, normally closed 'contacts '777, '77.8, 779 of electric motor means 766 and branch conductor 816.

The .automatic means for controlling horizontal swinging 'of the vein-attacking and disintegrating instrument is 'forrthis embodiment substantially the same as in the embodiment shown in Fig. l5, andl need therefore not be described kagain here.

The electrical system 'of Fig. 18

The system shown in Fig. 18 is a somewhat simplified versionl of the embodiment lshown in Fig. 17. It will be recalled that, in the discussion of Fig. 17, reference was nade to the Afact that the 'valves 620 and 622 were shown in the drawing as being connected in parallel with pump 3'6, but that asian actual matter of fact, the valves might be connected in series. For a series connection, an electrical system something like vthat shown in Fig. 17 is required 'for' proper operation of valves 620 and 622. However, if these 'valves can actually be connected in parallel as shown, then a considerably 'simplified system is possible. Such a system is shown iii Fig. 18.

This system eliminates 'the electric motor means 700, 702, '704 and 706. Instead of connecting the 'electromagnetic actuating means 634, 636, '63a and 640 through the aforesaid electricV motor means, the electromagnetic means 'are connected for actuation through the limit switches 664, 666,668 and 670. Inasmuch a's the limit switches shown in Fig. 18 are substantially identical with those shown 'in Fig. 17, they will not be described here in detail.

in the embodiment shown in Fig. 178, the coil 634 is connected across the power source 642, 726 by means of conductor 646i, limit switch 668, conductor 818, 'cnnductor 820, and conductor 822.v Similarly, the coil 636 i's `c'viurnec'ted across the powersource 642, 726 by means of conductor '644, limit' switch 666, conductor 824, conductor 826, and 'the aforesaid conductor 822.

In like manner, the coil 638 is connected across the power source by means of conductor 648, limit switch.

664, conductor 828, conductor 830, and lthe aforesaid conductor 822; and the `coil 640 is connected across the power source by means of conductor 650, limit switch. 670, conductor 832, conductor 834, Iand the aforesaid conductors 830 and 822.

The electrical means for accomplishing automatic horizontal swinging of the instrument 4 is substantially thesanre in Fig. 18 as in Fig. 15 and need not be described here in detail.

Operation-' The operation of the embodiment of Fig. 4

It will be assumed that the reader is familiar with the operation of manually operated continuous' mining machines made according to the inventions described in the above-identied patent v'applications to Russell and Sibley. L'et u-s' suppose that the veinatta-cking and disintegrating instrument has 'just been lowered from position A into position B `(Fig. 20) to begin 'the 'sumping-in operation, or 'noyer'nen't from position B to position C. As the instrument 4 nears the position B, the projection 'i6 (Fig. 44) engages the limit means (or master cylinder) 68. 'More specilically, the projection 76 engages the piston rod of the cylinder 68, displacing the piston in its cylinder 'and effecting a how of hydraulic fluid through the conduit 80 to vthe slave cylinder 82. This introduction of hydraulic u'id intol cylinder 82 causes movement tothe "right of :the nearing piston 86, and with lit lthe skirt l88 which constitutes the control mechanism for the fluid motor 102. As piston 86 rnoves'int'o the operat-y 14 ing .position represented by its extreme limit of travel to the right as 'seenin Pig. f5, the 'peripheral groeve 190 registers with conduits 96 and 98. `The accumulator 106 thereupon discharges hydraulic fluid under .pressure through conduit '98, control means '88, conduit '96, and conduit 100 to the iuid motor means 102.

The .piston v128 of the hydraulic motor 102 moves to the right, carrying 'the rack 134 to the right and rotating the pinion 136 clockwise through something more than 90. As Vthe `pinion 136 turns clockwise, the balls 142 in the recesses 140 engage the corners of shaft `138 and rotate it clockwise. The positive rotation of shaft 138 referred to causes the ball `detent 156 (Fig. 7) to be forced out of the recess 154 with which it was engaged, and to drop into the next lsucceeding recess 154. yThe shaft is then held in the new orientation. Rotation of shaft 138 clockwise as .aforesaid effects a rotation of the valve body 170 (Fig. 8) from the position shown in Fig. l1 into the position shown i-n Fig. 8. Fluid under .pressure thereupon flows from the Apump discharge liney 4G through lthe axial passage 198 (Fig. 12)-, into the axial passage '20'0 of the valve body 170, radially outward through the passage `202 in the valve body 170, through the radial passage 172 in -tne valve housing 162, through the'connectin'g passage 174, and through conduit 52 to the sump cylinders 16. With `valve body 170 in the position shown in Fig. 8, conduit 56 is blanked of and fluid vremaining lin cylinders 18 'is trapped.

As fluid :llows into the right end of sump cylinders 16, fluid also flows outof the left end of those cylinders by way of conduit 54, passage 184 in valve body 162, radial 4passage 182, tangential passage 206 in valve body 170, longitudinal passages 204 yand 196, the arcuate passage formedby grooves 188 and 188'-, the passages formed by groove 186 and .its cooperating groove in cover plate 168 and grooves 190, 190'-, and conduit 50 back to the tank 'or reservoir 34. As uid under pressure is admitted -to the sump cylinders 16, the vein-attacking and disintegrating bits moving in their orbital paths advance into the vein of coal or other mineral. As the instrument i4 begins to advance in the sump operation, thesprojection 74 is movedfaway from the piston rod of the master cylinder 70. The piston of .this cylinder is thereupon tree to lmove leftward `as seen in Fig. 4. As it moves leftward, spring 104 (Fig. 5) in cylinder 82 forces oating .piston `86 to the left as seen in Fig. 5, with the result that the lhydraulic fluid that was in cylinder 82 is displacedftherefrom through conduit into the master cylinder 70.

With the floating :piston 86 of slave cylinder 82 rcturned once more to the position illustrated in Fig. A5. the peripheral groove is in registry with conduits 92 and `v94, with the result that lthe cylinder of uid motor 1'02 is connected with reservoir 34. Spring 1350 of liuid moto-r 102 is thereupon able to push piston 128 leftward again, Vthe hydraulic uid ahead of ,piston 128 being discharged Vinto the tank by way of conduits 100, 92, 94 and 50, 'and the (groove 90 of the skirt 88.

As 'piston 128 moves leftward, it carries with it piston rod 4132 and rack 13'4. Rack 134 thereupon rotates pinion y136 counterclockwis'e. As pinion 136 rotates counterclockwise, at least one, probably two, and possibly three, of the balls 142 will be carried around the shaft corners into new operating positions, although it may be expected that gravity will cause the ball shown at the right side ofl Fig. '6 Vto drop down into the lower end of its recess 140, with the result that the top ball will also usually be 'out of operating position. Accordingly, at

`lea's't one of the balls 142 will always be ready to be engaged for another clockwise rotation of pinion 136.

The vein-attacking and disintegrating instrument 4 continues to sump in, and near the end of the sumping-in stroke, projection 74 engages the yii'rotruding piston rod of the vmaster cylinder 64. Continued movement to Vthe end of the sniping-in operation `forces the piston in cyl inder 64 leftward, displacing the hydraulic tluid therefrom into conduit 80 and into slave cylinder 82.

The operation of slave cylinder 82 described above is.

repeated with the result that the valve body 170 is indexed from the orientation shown in Fig. 8 to the orientation shown in Fig. 9, in which position conduits 52 and 54 are blanked oli, and uid is trapped in cylinders 16.

As is clearly evident from an inspection of Fig. 9 the valve 42 is now oriented into position to -admit fluid under pressure from conduit 40 to conduit 56, which connects with the upswing cylinders 18. inasmuch as the weight of instrument 4 is suticient to lower that instrument, there is no need to power the instrument down, so that the upswing cylinders 1S are single acting cylinders, and for this stage of operation the tangential passage 206 is blanked olif, i. e., is not in communication with any passage in the valve housing 162.

As the instrument 4 begins to swing upward through a vertical plane, the projection 76 moves out of engagement with the piston rod of master cylinder 68, allowing the slave cylinder S2 to return to the position illustrated in Fig. 5, as described above. Furthermore, the fluid motor 102 thereupon returns to the operating position illustrated in Fig. 5 and the valve 42 is in position to be indexed for the next operation.

As the instrument 4 approaches its upper limit of upswing, position D, Fig. 20, projection 76 engages the piston rod of master cylinder 66, effecting once more the operation of slave cylinder 82 referred to above and consequently the operation of uid motor 102 and the reorientation ot valve 42 from the position shown in Fig. 9 to the position shown in Fig. l0. As the valve body 170 rotates clockwise from the position shown in Fig. 9, the radial passage 202 moves out of registry with the radial passage 176 with the result that the radial passage 176 is blanked oil, as shown in Fig. 10. Fluid is thereupon trapped in the upswing cylinders and the instrument 4 is held in its uppermost operating position.

With the valve body 170 in the position shown in Fig. lO, fluid under pressure is admitted from the pump discharge line 4l) to the left end of the sump cylinders 16 by way of the conduit 54. At the same time the right ends of sump cylinders 16 are connected with the tank 34 by way of conduits 50 and S2, and the appropriate passages in valve 42.

With the connections shown in Fig. l0 and described above, hydraulic fluid under pressure is forced into the left ends of cylinders 16 and is discharged from the right ends, with the result that the vein-attacking and disintegrating instrument 4 moves through the operation called retract As the instrument 4 begins to retract, the projection '74 moves out of engagement with the piston rod of master cylinder 64, allowing the slave cylinder 82 to return to neutral and permitting the iiuid motor 102 to return to its neutral position, all as has been described above in detail. Fluid motor 102 is thereupon again in position to index the selector means 42 for the next operation.

As the instrument 4 nears the end of the retracting operation, the projection 74 engages the piston rod of master cylinder 70. etiecting operation of slave cylinder 82. With the piston 86 of the slave cylinder 82 moved to the extreme right, as seen in Fig. 5, hydraulic fluid under pressure is again admitted to uid motor 162, and the valve 42 is indexed into its next operating position, namely, from thc position shown in Fig. to the position shown in Fig. l l, again trapping uid in cylinders 16.

ln the position shown in Fig. ll, valve body 170 is so oriented that the tangential passage 206 is in communication with the radial passage 176, so that the upswing cylinders 18 are connected with the tank 34 by way of conduit 55, valve 42, and conduit 50. The weight of the instrument 4 is sufficient to force the discharge of hydraulic Huid from the cylinders 18. Those cylinders are therefore single acting cylinders, and the radial pas- 16. sage 202 of valve body isblanked off in the orientation of valve 42 as shown in Fig. l1.

As the instrument 4 begins to lower, the projection 76 moves out of engagement with the piston rod of master cylinder 66, allowing slave cylinder 82 to return to its neutral operating position as shown in Fig. 5, whereupon fluid motor 102 also returns to neutral and into position for the next indexing step. As the instrument 4 reaches its lowermost position, projection 76 engages the piston rod of master cylinder 68, operating the slave cylinder 82 and causing fluid motor 102 to index the valve 42 from the position shown,in Fig. l1 to the position shown in Fig. 8. The instrument 4 is thereupon ready to begin a new cycle of operation.

lt will, of course, be understood by those skilled in the art that, without the intervention of another` operation, the instrument 4 would be in position to move through an operation in a space which had already been cleared of coal or other mineral by the cycle of operations ljust described. Some means is required to index the instrument 4 horizontally about its vertical axis of swing into a new operating position. The horizontal swinging of the instrument 4 is accomplished by the swing cylinders 20.

Reference is made again to that portion of the cycle in which the sump cylinders 16 retract the instrument 4 from its extended position. As the instrument 4 nears its completely retracted position, the projection 78 on piston rod 60 (Fig. 4) engages the protruding piston rod of master cylinder 72. Master cylinder 72 is constructed and operates in a manner substantially the same as master cylinders 64, 66, 68 and 70. As master cylinder 72 is operated, it effects operation of slave cylinder 212, which is substantially the same as slave cylinder 82. As slave cylinder 212 is moved into position in response to the actuation of master cylinder 72, communication between conduits 230 and 232 is cut olf, and communication between conduits 224 and 226 is established. Fluid under pressure is thereupon free to move from accumulator 106` through conduits 119, 98 and 224, the control groove of slave cylinder 212, conduits 226, 228, 250 and 252.

lt should be noted that fluid under pressure is also admitted at this time to the valve 234. It will be assumed for the moment that valve` 234 is so oriented as to connect conduit 228 with conduit 240 and conduit 236 `with conduit 238. Conduit 240 is therefore under pressure but because the conduit is still blanked olf with piston 268 in the position shown in Fig. 4, there is of course no fluid flow through conduit 240.

Piston 268 is free to move leftward as seen in Fig. 4 under the influence of tlud pressure introduced by way of conduit 252. Accordingly, piston 268 moves to the left, compressing spring 270, until conduit 246 is connected with conduit 238 by way of groove 272, and conduit 248 is connected with conduit 240 by way of groove 274.`

Fluid thereupon ows from conduit 240 through groove 274 and conduit 248 into the right ends of the swing cylinders as seen in Fig. 4; at the same time uid is discharged from the lett ends of the swing cylinders by way of conduit 246, groove 272, conduit 238, valve 234, and conduits 236, 94, and 50 to the tank 34.

The swing cylinders 20 eect horizontal swinging (see Fig. i9) of the instrument 4 about its vertical axis at the same time that the instrument 4 is being lowered. This horizontal swinging brings about a relative movement between cam follower 278 and the cams 282, 284 and 286. It will be assumed that the relative movement is such that cam 286 and cam follower 278 are moving toward each other.

As the cam 286 engages the cam surface 280 of cam follower 278, cam follower 278 is pivoted clockwise as seen in Fig. 4 until the extension 298 engages the stop 296.

Continued swinging of the instrument 4 causes the cam 286 to push the cam follower 278, and therefore piston 268, to the right as seen in Fig. 4.

As soon as piston 268 is moved to the right sufficiently to move the grooves 274 and272 out of engagement with conduits 240, 248, and 238, 246, respectively, the horizontal swinging of instrument 4 stops. Cam follower 278 remains in contact with cam 286 until the pressure in cylinder 244 is relieved. It will be noted that, as soon as the sump cylinders 16 begin their sumping-in operation, projection 78 will move out of engagement with the limit means, or master cylinder, 72, allowing the slave cylinder 212 to return to its neutral position, in which communication is cut olf between conduits 224 and 226 and is established between conduits 230 and 232, whereupon cylinder 244 is vented by way of conduits 252, 250, 228 and 230, the control groove of slave cylinder 212, and conduits 232, 94 and 50 to the tank 34. Conduit 254 and check valve 256 connect with pump line 40 in order to provide a safety pressure outlet in case piston 268 be moved to the right at a time when, for any reason, conduit 250 might be blocked.

Spring 270 is now free to push piston 268 further to the right as seen in Fig. 4, permitting cam follower 278 to be snapped into its central operating position as shown in Fig. 4 by its centering spring, not shown. Cam follower 278 is then positioned so as to be able to clear the cam with which it was just in engagement the next time piston 268 moves leftward.

It can thus be seen that as each of the cams 282, 284, 286 etc. engages cam follower 278 the lateral movement of the disintegrating instrument is interrupted after the latter has moved through a normal operating stroke distance, i. e. considering that the full relative movement of the cylinders 20 and their associated pistons causes lateral movement of the disintegrating instrument through a distance which is a multiple of the normal operating stroke distance required to move the disintegrating instrument into position to start another cycle, the disintegrating instrument moves through a normal stroke distance into a new cycle starting position as each of the successive cams 282, 284, 286 etc. comes in contact with the cam follower 278 and causes an interruption of fluid flow to cylinders 20.

As will be understood by those skilled in the art, the mechanism may be oriented for swinging in the opposite direction by reversing the four-way valve 234 to bring conduits 228 and 238 in communication, and conduits 236 and 240 in communication; and by swinging the cam follower 278 through 180 about the axis of piston rod 276.

It will further be understood by those skilled in the art that horizontal swinging of the instrument 4 may be accomplished manually independently of the automatic mechanism by manipulation of valve 258.

The operatonof the embodiment of Fig.

The embodiment shown in Fig.l5 employs a selector valve 42 which is identical with the selector valve shown in Fig. 4, but is electrically operated. As instrument 4 reaches its lowermost position in the lower operation of its cycle, projection 76 engages the limit switch 368, closing the normally open contacts 406, 410, 408 and 446, 448, 386.

It will be recalled that the instrument 4 is in the retract position as it swings down through the lower operation of the cycle. With the instrument 4 retracted, the limit switch 370 is in its closed position, i. e., the position shown in Fig. 15. The closing of limit switch 368 referred to above completes an electric circuit from the positive side 317 to the negative side 329 of the power source through conductors 318 and 374, coil 332, conductor 376, conductor 390, closed contacts 388, 416, 414 of limit switch 370, conductor 412, closed contacts 408, 410, 406 of limit switch 368, and conductor 404. With coil 332 thus energized, armature 334 is moved to close contacts 322, 330, and 324. A circuit is thereupon established from positive side 317, through condoctor 318, coil 312 of electromagnetic device 310, con- 18 ductor '320, closed contacts 322, 330, 324, and conductors 326 and 328 to the negative side 329.

With coil 312 thus energized, armature 314 is moved to the right to index the selector valve 42 into the position, shown in Fig. 8. Fluid under pressure is thereupon admitted to eiect sumping of the instrument 4. As the sumping-in operation begins, projection 74 moves out of contact with limit switch 370, allowing the contacts there of to open. This opening of the contacts breaks the circuit outlined above for coil 332 and allows the contacts 322, 330, and 324 to open, which in turn breaks the circuit for coil 312. With coil 312 thus tie-energized, spring 316 is free to retract the rack 134 into the position shown in Fig. l5, whereupon the electromagnetic device is ready to orient the selector valve 42 for the next operation.

As the instrument 4 nears the end of its sumping-in operation, projection 74 on piston rod 60 closes the contacts of limit switch 364. An electric circuit is then established from positive side 317, through conductors 318 and 374, coil 332, conductors 376 and 380, contacts 386, 448, 446 of limit switch 368, conductor 444, contacts 440, 442, 436 of limit Iswitch 364, and conductor 438 to the negative side 329.

Bridging contact 330 theerupon moves again into circuit closing position, and a circuit is established again for the coil 312 as described above. With coil 312 thus energized again, valve 42 is indexed from the position shown in Fig. 8 into the position shown in Fig. 9, so that lluid under pressure is admitted to the upswing cylinders 18.

As the instrument 4 begins to move through the upswing operation, projection 76 moves out lof contact with limit switch 368, allowing the contacts of limit switch 368 to open and thus opening the circuit for coil 332 just detailed above. Coil 332 is again de-energized, again breaking the'circuit for coil 312 and again returning the electromagnetic device 310 into position for orientation of the valve 42 for the next operation.

As the instrument 4 nears the uppermost limit of upswing, projection 76 engages the limit switch 366 and closes its contacts. A circuit is thereupon established from the positive side 31'7 through conductors 318 and 374, coil 332, conductors 376 and 378, contacts 382, 394, 392 of limit switch 364, conductor 396, contacts 398, 402, 400 of limit switch 366, and conductor 404 to the negative side 329.

Bridging contact 330 is thereupon again moved into circuit closing position for coil 312, indexing the valve 42 from its orientation shown in Fig. 9 to the orientation shown in Fig. l0. Fluid is thereupon admitted to the sump cylinders 16 to move them through the retract operation of the cycle. As the sump cylinders begin to retract, projection'74 moves out of contact with limit switch 364, allowing the contacts thereof to open and thus opening the circuit for coil 332 just detailed. This de-energization ofcoil 332 again allows the contact 330 to drop out, thus opening the circuit for coil 312. Ele tromagnetic device 310 is thereupon returned again into position for once more indexing the valve 42 for the next operation.

As the instrument 4 approaches the end of the retract1 operation, projection 74 engages limit switch 370 and closes the contacts thereof. A circuit is thereupon established from positive side 317 through conductors 31 and 374, coil 332, conductors 376 and 378, contacts 384,

l420, 418 of limit switch 366, conductor 422, contacts 424,

428, 426 of limit switch 370, and branch conductor 430 to the negative side 329.

Coil 332 is thus again energized to complete an electric circuit for coil 312 and to move selector valve 42- from the position shown in Fig. 10 to the position shown in Fig. 1l. With the valve in the position shown in Fig. l1, the upswing cylinders 18 are vented to the tank 34, and the weight of instrument 4 causes it to lower as lluid is discharged from cylinders 18 to tank 34. As instru- 

